Osgood-Schlatter disease is caused by repetitive stress or tension on a part of the growth area of the upper tibia (the apophysis). It is characterized by inflammation of the patellar tendon and surrounding soft tissues at the point where the tendon attaches to the tibia. The disease may also be associated with an avulsion injury, in which the tendon is stretched so much that it tears away from the tibia and takes a fragment of bone with it. The disease most commonly affects active young people, particularly boys between the ages of 10 and 15, who play games or sports that include frequent running and jumping.
People with this disease experience pain just below the knee joint that usually worsens with activity and is relieved by rest. A bony bump that is particularly painful when pressed may appear on the upper edge of the tibia (below the knee cap). Usually, motion of the knee is not affected. Pain may last a few months and may recur until a child's growth is completed.
Osgood Schlatter disease is most often diagnosed by the symptoms. An x ray may be normal, or show an avulsion injury, or, more typically, show that the apophysis is in fragments.
The disease usually disappears without treatment. Applying ice to the knee when pain first begins helps relieve inflammation and is sometimes used along with stretching and strengthening exercises. The doctor may advise the patient to limit participation in vigorous sports. Children who wish to continue participating in moderate or less stressful sports may need to wear knee pads for protection and apply ice to the knee after activity. If a great deal of pain is felt during sports activities, participation may be limited until any remaining discomfort is tolerable.